


what does death know of love? (everything)

by Chaos_Greymistchild



Category: Kuroshitsuji | Black Butler, Noblesse (Manhwa)
Genre: Alternate Universe - Modern Setting, Fake/Pretend Relationship, Mild Gore, Other, Other Additional Tags to Be Added, Overprotective, Queerplatonic Relationships, Tags Are Hard, and someone to take his battles for him, for black butler, i guess, in this essay I will, it's not like they wouldn't act like this anyway there just isnt romance, kind of???, rai needs cuddles, so he DOESNT FUCKING KILL HIMSELF, the romance part is faked at least
Language: English
Status: In-Progress
Published: 2020-03-05
Updated: 2020-04-16
Packaged: 2021-02-28 16:41:35
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 2,616
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23020381
Author URL: https://archiveofourown.org/users/Chaos_Greymistchild/pseuds/Chaos_Greymistchild
Summary: Undertaker and Frankenstein band together to aggressively take care of Rai. That's it. That's the fic.
Relationships: Cadis Etrama Di Raizel & Frankenstein (Noblesse), Cadis Etrama Di Raizel & Frankenstein (Noblesse) & Undertaker (Kuroshitsuji), Cadis Etrama Di Raizel & Undertaker (Kuroshitsuki), Frankenstein (Noblesse) & Undertaker (Kuroshitsuji)
Comments: 16
Kudos: 97





	1. in which there are godsawful ringtones, grave markers raining from the sky, and jealousy

**Author's Note:**

> did you know. that those things undertaker uses in addition to his death scythe. yknow. those wooden things. they're grave markers called "sotoba". I didn't know this either. god bless wikipedia.

Faintly, the "Baby Shark Do Do Do" jingle rang about the tense room.

"Ah, sorry," Undertaker said cheerfully without the slightest trace of apology in his voice, "That would be me. Do you mind if I....?"

The gang boss across from him nodded and gestured to the gang member holding a gun to his head. The gang member reached into the pocket of his trench coat and pulled out his phone, flicking it open and holding it next to his ear.

"Hello~~" he chirped into the receiver, taking the opportunity to lean into the barrel pressed against him.

"Undertaker."

Frankenstein sounded oddly rattled.

"Yes, dear?" he asked, sing-song.

"He's back. Master's back. He just woke up and ended up at my school."

Undertaker narrowed his eyes, mood instantly switching from cheerful to focused and murderous. He barely registered the gang member next to him flinching badly. He did not doubt Frankenstein in the least.

Which was the problem.

"I'll get the soonest flight over," he told him.

"No," Frankenstein barked.

"No?" he asked, soft and deadly. Out of the corner of his eye, he could see the gang boss shiver at the tone of his voice.

"Undertaker, you're the reason why I -- we -- can afford running the school at a deficit. Would you ask Master to live in anything less than the greatest luxury we could provide?" Frankenstein sounded like he was being forced to eat glass, just admitting that.

"No, I wouldn't," he ground out. "I'll finish up on my side and be back in a week or two."

"So long?" This time Frankenstein took on a distinctly teasing lilt that he recognised as his _SSS-Grade Trash Talk Skill_ as someone had once pointed out.

He didn’t bother to answer, just stopped leaning into the phone and the gun, which its wielder took as the signal to flip it closed and throw it over to his boss.

“What’s this about leaving here alive?” the gang boss asked, attempting to mimic his quiet danger.

Undertaker beamed. “My dearest Raizel has returned, naturally I can’t die before meet him again, at least.”

“You act like you seem to believe you have a choice in the matter,” the boss said idly.

His grin widened, into something with too many, too sharp teeth. “ _You_ act like you seem you believe you have a choice in the matter.”

The boss sputtered for a moment, before a snarl crossed her previously beautiful features. “You’re outnumbered and overpowered, you cocky bastard. I’ll send you to _hell_.”

The gun fired.

He laughed lightly and showed the two the bullet he held delicately between two fingers. “Oh my, you seem to be missing something. Allow me to return it to you.”

A flick of his wrist made the ruined, used bullet fly through the gang member standing over him as if it had never been shot. Panic stole over the gang boss’ face, suddenly breathtakingly beautiful. Although nothing would ever match up to his Raziel’s rare smile, this came close.

“What were you saying about sending me to hell? I’m afraid I’m going to need to send you ahead of me. Do me a favour and say hello to William for me, will you?”

“FIRE!” The boss shrieked.

Endless volleys of gunfire spread around him, some even spearing through him despite his efforts to dance around them. He made quick work of the gangsters around him, sotoba whirling. The Death Scythe can cut everything in the world. His sotoba might not have an edge, but even blunt things could pulp their way through soft human flesh.

Undertaker leaned slightly onto his Death Scythe and ran his fingers through his bangs, pushing them back from his face. He dabbed carefully at the spots where he could still feel the drying blood and sighed. A potential thread, lost to Frankenstein’s untimely interruption. He’d need to ferret out the double-agent who’d been feeding the boss information _without_ any new information.

Unfortunately, it was looking closer to two weeks. If it were any other reason, any other person, he might be content with that, but his darling Raizel.... he just wanted to feel that stuttering, sickly heartbeat bloom into health under his hands again.

He kicked the body at his feet over until it was facing him and dug his phone out of her pockets to take a picture. He hadn’t meant to destroy the gang like this but he was sure that if he chased up the right leads someone would be willing to pay him for it.

Sotoba rained down from the sky. Frankenstein disengaged with the blue-haired woman to dodge the indiscriminate projectiles.

Undertaker landed with a quiet _tap_ on the rooftop, trench coat swapped out for a funeral director’s robes, hair loose in the wind, and glasses firmly fixed to his face. “Frankenstein,” he greeted.

Frankenstein’s smile twitched. “Undertaker.”

“Raizel is in this building?” He felt that gentle tug and wash of Raizel’s aura against his soul.

Frankenstein’s smile turned even more strained. “Master is inside, yes. Our guide is with him.”

They shared significant looks, a silent _thank the moon and stars_.

“No one cares about the building, although there _are_ children inside, _Undertaker_.”

He waved carelessly. “Don’t worry, Frankenstein. If Raizel’s taken a liking to them, I won’t do a thing. I’ll be going on ahead now.”

He lifted a leg and kicked his way through the floor, then dropped down, and again, and again, until he reached a level where he felt his Raizel’s energy as horizontal to him, instead of diagonal. A ripple passed through Raizel’s still lake of energy, and he flared his own in response.

He picked up the pace. Something told him he didn’t want to miss this.

A voice, quiet, yet overpoweringly strong. “Kneel.”

The modified human that was facing Raizel — _daring_ to face off against — _daring_ to _attack_ his Raizel — slammed into the ground. Undertaker skidded to a halt near his Raizel, the speed of his momentum driving him onwards even as he stumbled and his legs collapsed beneath him under the force of his dearest’s power.

“Undertaker.”

He could hear the slightest surprise in his Raizel’s normally composed voice.

“My dear,” he breathed, relaxing utterly beneath the tranquil mantle of Raizel’s power.

“I give permission back to you.”

He slunk over to Raizel and curled up at his darling’s feet.

The presumptuous human roared and turned grotesque, turning purple and growing horns and spikes. It dared to stand up. It dared to strain against his Raizel’s power.

“Rai…”

He twisted around to see the three human children he had barely glanced over before. They must have been the ones Raizel came for. But to use such a familiar address! It made him want to tear out their tongues for daring to be closer than he was.

Raizel drew a hand across them, and they all collapsed again. He must have put them to sleep and modified their memories in the same movement. Undertaker was a little put out by the casual dismissal of his chances of maiming them.

The modified human roared and when Raizel reached up for the blood on its teeth, he tugged at his Raizel’s pants. He wanted to be the one to… take care of it.

His Raizel paused and considered it for a moment, before stepping back, away, from him and nodding.

He was up in a flash, sotoba flashing green into his familiar skeleton-topped scythe, the balance and form even now well-worn into his bones. He restrained the power of his Death Scythe, chained it to blade and haft and no more. Raizel would be so very disappointed if he split the building in two.

The modified human still died too soon, limbs severed and screaming as its own healing factor kept it alive.

The soft _tap, tap_ of Frankenstein’s dress shoes echoed down the corridor in the silence after it died and stopped screaming.

“Master, I have finished the job.”

The man next to his Raizel whirled around in shock. Undertaker just shared a nod with Frankenstein, acknowledgement that they had both done their jobs and Raizel hadn’t been forced to use more than the barest sliver of his life force.

The faintest voice, barely audible for even his senses, spoke up. It took him an embarrassing long amount of time to realise that it was coming from the comms in the grey-haired man’s ear. He ignored the man to walk back over to his Raizel and kiss him softly. Rai leaned into him, ever so slightly, then swayed away again. Undertaker sighed and moved to embrace his Raizel from behind, head tucked under Raizel’s jaw.

He didn’t let go until they left, leaping across the rooftops.


	2. in which there are long-forgotten scents, denial, and the soft beginnings of an age-old love

As much as he would have liked to stay close to his Raizel and simply _luxuriate_ in his presence after so long apart, he had matters to take care of in South Korea, ones that he had shunned in favour of racing for his Raizel. He was severely regretting not having the patience to take care of business and wait a day or two. What was that compared to 820 years, after all?

He reluctantly peeled himself from his Raizel and stepped to the side while the grey-haired man — M-21, he later found out — and Frankenstein discussed matters. Undertaker flipped open his phone and began making calls to the appropriate people. He made sure that he was far enough away from the discussing trio that even the most enhanced senses wouldn’t be able to make out what they were talking about over the phone, but close enough that he could easily follow along the conversation at the same time.

Raizel stood up, and he followed that movement like a hawk, even as he began winding down his conversation on the phone. He ghosted through the halls behind him, ignoring M-21 hovering awkwardly and Frankenstein’s anger as he stepped into Raizel’s room.

He closed the door behind him, gently, because he would never even imagine harming something of his Raizel’s, but pointedly. Raizel turned, as if he hadn’t noticed him quietly following behind. He smiled, knife-sharp, and cornered Raizel against the side of the bed. Raizel obediently sat down and he crouched over him, a hand bracing himself on the mattress beside Raizel’s hip.

“ ‘Rai’?” he asked in a murmur.

“The children thought my name was too long. Shortened.” Raizel replied in his quiet voice, made softer by their close proximity, and laconic as always.

“Can I?”

A simple nod.

“Rai,” Undertaker murmured wondrously into his neck. He reached up with his other hand and ran it through Rai’s feather-soft hair.

Rai leaned into it ever so slightly.

He hesitated. He didn’t want to ask Rai of this, not after the way they had parted. But it had been _so long_.

Rai must have felt his desire and matching reluctance, because he rolled them over until they were lying side by side.

“You can stay,” Rai said, as soft and unassuming as always. As if he hadn’t just—hadn’t just offered to give himself up for the night just for him, who had _failed_ —

A warm arm wrapped around his waist, and a hand settled between his shoulder blades. He couldn’t help it. He made an embarrassing squeaking noise and flung himself into the hug. He didn’t dare dislodge Rai’s arms around him, so he just burrowed into Rai, tangling their legs together and trying desperately to bend down enough to press his nose into Rai’s hair and breathe in that scent he’d long-since forgotten.

The hand on his back left for a moment, and he whimpered pathetically, but he didn’t _care_ because the hand was back and he was breathing in Rai who was _alive_ and _here_ and _nothing else mattered_.

Another presence, _darkdarkdark_ wrapped in the thinnest layer of ceramic facade under steel and shifting tides, joined them on Rai’s other side. Frankenstein pressed close, cradling Rai between them and with one hand on his shoulder and a leg thrown over the both of theirs.

He let himself relax, slowly, but by bit, rocked by the tides of power and cradled in metaphysical silken steel.

He completely missed the raid on the lab. _He completely missed it_.

It’s true that Frankenstein could handle such a little thing on his own, doubly so if Rai was with him and released his seal. It’s also true that his own meetings were important if he didn’t want the local underground to take offence to his presence and pointedly poke their poisonous fingers into Frankenstein’s business.

If they toyed with Frankenstein, they played ball with Rai, that was the only reason why he made sure to be respectful, that’s all.

Undertaker knew that he was in denial but as long as he was aware of it, he thought that it was probably fine. He managed to secure lab space from Frankenstein without missing a beat.

He only emerged from setting up his lab and moving his experiments into it after a few days. By that time… it was probably too late to wander into the house and introduce himself to the children that he’d been living there for the past few days and they’d simply not seen him around.

Instead, he waited another day, until school was about to end.

“Rai,” he greeted, stepping around to stand in the way of the small crowd of children, “wrist, if you please.”

Rai’s wrist was instantly cradled gently in his loose grip. He felt for Rai’s pulse and found it strong and steady. Undertaker smiled and let Rai’s hand slip through his loose fingers until he held onto his fingers only, then bent down and drew it up to brush his lips over Rai’s knuckles.

Rai sighed, barely a huff of air, but he could see the slight smile on his face and knew it was only fondness.

The children all let out sounds of shock. “Eh?! EH?! EEEEEEEH?!?!”

“Rai hasn’t told you about me?” he asked, pouting childishly. “I’m Ariel, one of his doctors and his boy~friend~~” he winked.

They let out simultaneous, louder sounds of shock.

He swung them around until he was draped around Rai, holding him up like they were dancing. Rai let him manhandle him, loose-limbed and malleable. That, more than anything else, seemed to convince the children that they were intimate.

When he pouted and asked Rai why he hadn’t told his friends and Rai had just hummed a non-answer, it was all just window dressing.

“Ah, well why don’t we go ahead and you two can spend the day together? We’ll have dinner at Yuna’s instead,” one of the children suggested.

“Public,” the model-pretty human girl reminded the one who spoke with aggravation.

“Ahh, you won’t mind if we go to the Chairman’s and crash your date, will you, Rai?” the other girl asked sheepishly, one hand tucking a strand of hair behind her ear and she was cute in that kind girl next door way and he wanted to _kill her destroy her how dare—_

Rai patted his face and he obligingly turned his attention to his Rai. Rai stood up on tiptoe and kissed him.

His lips were soft, and the gentle tidal warmth of his power pressed deep and soothing against him. It stalled him in his tracks. After only a moment, Rai pulled away, and he followed him for a brief half second, before he registered Rai’s intention. He whined, a little.

Rai just patted him on his cheek again and settled back on his feet. “Let’s go home,” he said, soft as ripples on still water.

What could he do but obey?

**Author's Note:**

> You can find me on [twitter](https://twitter.com/greymistchild)


End file.
